Conductor Michael Tilson Thomas announces he will soon cease performing

Michael Tilson Thomas has announced the imminent end of his conducting career. The 80-year-old musician, who disclosed a diagnosis of cancer in 2021, will cease performing after concerts scheduled for March and April, he announced in a letter released Monday.

The conductor has been in treatments for glioblastoma for the past several years, and the tumor has returned, he wrote. While there are treatment options, “the odds are uncertain.”

He expects that appearances in coming weeks with the New World Symphony and San Francisco Symphony will be his last.

“At that point, we all get to say the old show business expression, ‘It’s a wrap,’” he wrote.

Tilson Thomas had also been slated to lead the Philadelphia Orchestra March 7, 8, and 9 in Beethoven, Ravel, and his own work, Agnegram, in Marian Anderson Hall. Those concerts will go on without him, with conductor Osmo Vänskä appearing in his place. The program remains unchanged.

The Los Angeles-born Tilson Thomas was music director of the San Francisco Symphony and Miami’s New World Symphony, and has had a presence in Philadelphia since his first appearance with the Philadelphia Orchestra and pianist Van Cliburn at the Robin Hood Dell in 1971. He continued to conduct and perform as a pianist with the orchestra at its summer homes throughout the 1970s and 1980s with soloists like soprano Beverly Sills, Sarah Vaughan and her trio, violinist Henryk Szeryng, and other big names.

The conductor was absent from Philadelphia for more than two decades after a 1985 program, but starting in 2008 he began to return regularly for subscription concerts in both standard repertoire and his own works.

Tilson Thomas emerged as a wunderkind — he became assistant conductor of the Boston Symphony Orchestra at age 24 — and somehow has managed to retain something of that persona.

“The boy-wonder conductor is about to turn 70,” wrote Inquirer music critic David Patrick Stearns in a 2014 review of the conductor with the San Francisco Symphony in Mahler at Princeton’s McCarter Theater. “Yes, compulsively youthful Michael Tilson Thomas is now an elder statesman, though still very much a musician who has fascinated and challenged the music world while maintaining a constant evolution that makes his work ever more fully realized.”

He has continued to perform throughout his illness, drawing considerable praise.

“Pungent details” and an “aching outpouring” were among the aspects of a Mahler Symphony No. 5 performed at this season’s opening night of the New York Philharmonic.

“There have been more taut and blazing Fifths, but this one had searching, saturnine weight; it left an appropriately disorienting impact,” wrote New York Times music critic Zachary Woolfe. “Some conductors can convey Mahler’s intensity without overkill, and some cannot. Mr. Thomas certainly can.”

Now the time has come to wind down public appearances, Thomas wrote in his letter.

“A ‘coda’ is a musical element at the end of a composition that brings the whole piece to a conclusion. A code can vary greatly in length. My life’s coda is generous and rich.”